1. Field of the Invention
The present invention relates to an ice making machine of the type wherein fresh water is supplied into a water tank through an upright ice making plate during the defrost cycle of operation and circulated as ice making water from the water tank to the ice making plate during the ice making cycle of operation to be frozen into ice cubes, and wherein the water remained in the water tank after the ice making cycle of operation is discharged during the drain cycle of operation. More particularly, the present invention relates to an electric control apparatus for the ice making machine for controlling the drain cycle of operation in accordance with the quality of water in the water tank.
2. Discussion of the Prior Art
In Japanese Patent Laid-open Publication No. 63-105381, there is disclosed an ice making machine of this type which includes a water valve arranged to be opened during the defrost cycle of operation for supplying fresh water from a water service pipe into a water tank through an upright ice making plate and a water pump arranged to circulate the fresh water from the water tank to the ice making plate during the freezing cycle of operation and to discharge the remaining water from the water tank after the freezing cycle of operation thereby to eliminate accumulation of contaminants in the water tank. In the ice making machine, however, the water pump is inevitably operated after the freezing cycle of operation to discharge the remaining water form the water tank irrespectively of the quality of water. This results in waste of the fresh water supplied into the water tank during the defrost cycle of operation.